A personalised approach to spine surgery

Abstract

Background: Anterior lumbar interbody fusion (ALIF) remains one of the mainstay surgical approaches in treating painful degenerative disc disease with or without segmental instability in the lower spine. The risk factors and complication profile for ALIF differs significantly from other established fusion techniques.

Objectives: The goal of the first part of this thesis is to establish the factors associated with long-term clinical outcome (Chapter 2) and short-term perioperative outcomes (Chapter 3) following ALIF. Chapter 4 focuses on the long-term radiographic evidence for biomaterial alternatives for ALIF implants, namely titanium (Ti)-coated PEEK integrated cages.

Methods and Results: From a prospective cohort analysis of 147 patients undergoing ALIF, elderly age (≥64 years old) was associated with an increased rate of subsidence but does not affect clinical outcomes. Obesity was not associated with postoperative complications or follow-up patient-reported outcomes. Failed fusion was significantly higher for smokers, and they were significantly more likely than non-smokers to experience postoperative complications such as pseudoarthrosis. To assess risk factors for perioperative complications and readmissions after ALIF, the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was analysed. ALIF was associated with prolonged length of stay and higher rate of return to operating theatre compared to posterior lumbar fusion. Obesity and alcohol intake increased the risk of 30-day readmissions. Discharge to non-home destination following ALIF was independently associated with wound complications and venous thromboembolism. Finally, a prospective follow-up study was performed to determine the long-term radiographic outcome following ALIF using Ti-coated PEEK cages with allograft and INFUSE. Effective fusion was achieved at up to 24-month follow-up for various indications including degenerative spine/disc disease, low grade lumbar isthmic spondylolisthesis, spondylotic radiculopathy and discogenic low back pain.

Conclusions: Collectively, this thesis highlights the importance of personalising the care of an ALIF surgery patient, through identification and optimization of individual risk factors for short-term and long-term outcomes, as well as through choice of implant biomaterial and design.